Familial idiopathic basal ganglia calcification (FIBGC) is a neurodegenerative disorder characterized by calcium deposits in the basal ganglia, a part of the brain that helps start and control movement. The first symptoms often include clumsiness, fatigue, unsteady walking (gait), slow or slurred speech, difficulty swallowing (dysphagia) and dementia. Seizures of various types frequently occur. Symptoms typically start in an individual's 20's to 40's but may begin at any age.The neuropsychiatric symptoms and movement disorders worsen over time.[1] Mutations in the SLC20A2and PDGFRB genes have been found to cause FIBGC, and this condition is inherited in an autosomal dominant manner.[2]

Last updated: 10/18/2013

What causes familial idiopathic basal ganglia calcification [FIBGC]?

FIBGC is a genetic condition; mutations in the SLC20A2gene are thought to cause about half of the cases of FIBGC. Mutations in the PDGFRB gene have also been shown to cause FIBGC. In the remaining cases, the genes responsible have not yet been found. However, there is a strong association to changes in chromosomes 2, 7, 9 and 14 and FIBGC.[2]

The diagnosis of FIBGC relies upon: 1) visualization of bilateral (on both sides) calcification of the basal ganglia on neuroimaging 2) presence of progressive neurological dysfunction 3) absence of a metabolic, infectious, toxic, or traumatic cause4) a family history consistent with autosomal dominant inheritance (a person must inherit one copy of the altered gene from one parent to have the condition). Rarely, symptomatic individuals in families with FIBGC do not show calcification. Thus, in some instances, the diagnosis can be made in the absence of one (but not both) of the first two criteria, providing the remaining criteria are met.[1]

Last updated: 8/2/2013

Is there genetic testing for familial idiopathic basal ganglia calcification even though the causative gene(s) are unknown?

Clinical genetic testing is available for the SLC20A2 gene, although a mutation is detected in only about 40% of cases of FIBGC.[1] If a mutation is not found, linkage analysis may be available on a research basis in families with at least two affected family members of different generation. This type of testing has shown linkage to chromosome 14q in one family. A genetics professional can assist in determining whether linkage analysis is appropriate for a family.[1]

Last updated: 8/2/2013

How can I find a genetics professional in my area?

Genetics clinics are a source of information for individuals and families regarding genetic conditions, treatment, inheritance, and genetic risks to other family members. More information about genetic consultations is available from Genetics Home Reference. To find a genetics clinic, we recommend that you contact your primary healthcare provider for a referral.

The following online resources can help you find a genetics professional in your community:

The American Society of Human Genetics maintains a database of its members, which includes individuals who live outside of the United States. Visit the link to obtain a list of the geneticists in your country, some of whom may be researchers that do not provide medical care.